Field of the Invention:
The present invention relates to a device for preventing the scattering of molded articles ejected from a resin molding machine which produces a plastic, and, more particularly, to a device for preventing the scattering of molded articles for use in an injection molding machine which comprises synthetic resin film screens for curtaining a gap formed when a mold is divided so as to prevent the scattering of the molded articles when they are ejected from the mold immediately after they being processed by the injection molding machine, and magnetic assemblies for fixing the screens by utilizing the attractive force thereof.
Description of the Prior Art:
Known and commonly used injection molding machines comprise a frame 2, an injection mechanism section 3, a mold clamping mechanism section 4, a hydraulic drive section 5, an electric control section, and so on, as shown in FIGS. 14 and 15.
The injection mechanism section 3 is generally designed to inject a melting material from an injection nozzle 32 provided at the distal end of a heating cylinder 31 through a main sprue (not shown) into a runner which communicates with a plurality of cavities through gates.
The mold clamping mechanism section 4 includes a fixed die plate 6, a movable die plate 7, tie bars 8 (8.sub.1 to 8.sub.4) inserted through the fixed and movable die plates 66 and 7 at the four corners thereof, a fixed mold 9.sub.1 mounted on the fixed die plate 6, and a movable mold 9.sub.2 counted on the movable die plate 7. After the molding by the fixed mold 9.sub.1 and the movable mold 9.sub.2 has been completed, the mold is opened, then molded articles are removed from the mold by an ejector 10 into a discharge section 160 where they are accommodated in a certain container.
In the case of resin molded articles of the type which need to be kept clean, attention must be paid to ensure that not even one soiled molded article is included so as to avoid the problems which might otherwise occur when they are assembled to form a finished product.
However, in the conventional injection molding machine, since both sides of the opened molds 9.sub.1 and 9.sub.2 fixed to the fixed and movable die plates 6 and 7 are open, when the molded articles are released from the mold by the ejector 10, the runner and the molded articles are separated from each other at the connecting gates and the separated molded articles are often struck against the lower tie bars and are soiled by a lubricant for the movable die plate or fall on the base surface of the frame and are dirtied by the oil coated thereon. Alternatively, the molded articles do not drop into the container but are scattered therearound.
If the molded parts are of the type which need to be kept clean, inclusion of even one that is soiled may lead to an accident or failure during assembly.
Even if the number of molded articles accommodated in the container is counted by a counter, a tendency for some to scatter around the container makes a precise count impossible, and may lead to a shortage of parts during assembly.
Accordingly attempts have been made to provide a barrier around the exterior of the mold of the injection molding machine so as to prevent the released, molded articles from scattering and being soiled.
Such a scattering prevention screen has been proposed in the specifications of, for example, Japanese Utility Model Laid-Open No. 159225/1981 (which corresponds to Japanese Utility Model Application No. 58996/1980 entitled Movable Curtain for Plastic Molding Machine) and Japanese Utility Model Laid-Open No. 194011/1983 (which corresponds to Japanese Utility Model Application No. 92043/1982 entitled Guide Skirt for Plastic Molding Machine). In both cases, the screening device is fixed by inserting bolts or vices into threaded holes in the molds or die plates. However, drilling of the threaded holes in the molds or die plates is a time-consuming task and requires skill. When position of the screening device is shifted, more threaded holes must be drilled at new positions, making the mounting of the screening device even more troublesome. Further, the molds have to be inspected or maintained frequently, and the stationary screening device must therefore be removed and mounted each time such inspection or maintenance takes place. This is time-consuming and may cause problems in terms of production efficiency and safety.